William



(No Model.) I W. O. LOOKWOOD.

TELEPHONE.

No. 331,309. Patented Dec. 1 1885.

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\VILLIAM O. LOOKWOOD, OF BROOKLYN, ASSIGNOR TO THOMAS WVALLAOE, OF NEWV YORK, N. Y.

TELEPHONE.

SPECIFIGATJION forming part of Letters Patent No. $231,309, dated December 1, 1885.

Application filed July 21, 1884.

To all whom itjnay concern;

Be it known that I, W-ILLIAM O. LOOKWOOD,

a citizen of the United States, and a resident of the city ofBrooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Telephones, of which the following is a specification.

My invention relates to telephones, and has for its object to improve the construction of such instruments, to render their action more delicate, and to avoid the disturbances due to the influence of extraneous currents; and to these ends my invention consists in a telephone having set electrodes which are normally held in operative contact by counteracting devices, which act axially, one tending to force the elec trodes apart and the other tending to press them together, the latter slightly preponderating and capable of delicate adjustment.

It further consists in the combination oftwo or more of such instruments on a charged line, one of which is adapted more particularly to operate as a transmitter and the other as a receiver, and by this combination I am enabled to avoid the disturbing effects from extraneous induction, thereby permitting the use of the instruments upon lines that run parallel to and in the neighborhood of other electric circuits.

Referring to the accompanying drawings, forming part of this specification, Figure l is a View, partly in section, of one form of my invention. Fig. 2 is a sectional view of another form. Fig. 3 is a front view with the mouth-piece removed; and Fig. 4 is a diagram of a circuit, showing one manner of using my invention.

Any suitable form and construction of case may be used; but I prefer one substantially of the shape shown in Fig. 1, which consists of a block, A, of wood or other suitable material, hollowed out or recessed to receive the electrodes and their connections, to which is attached the usual mouth or car piece, 13. A handle, 0, is connected to the block or body, and bindingposts E are secured thereto in any convenient place. A diaphragm orsounding-board, D, is held between the block and the mouth-piece in a well-known manner.

I preferably construct the electrodes with comparatively large fiat faces, the upper one,

Serial No. 138,369. (No model.)

a, of which may be of any well-known form of carbon, though I prefer to use carbon treated with glycerine in a manner described in a former application filed by me. The other electrode, 1), is of platinum, iridium, or similar refractile metal, and is in the form of a comparatively thin disk or plate. Suitable conducting-wires lead from the electrodes at b to the binding-posts E, which are connected directly to the line or ground wires. The electrodes are secured to blocks or supports 0 c, of some non-conducting material, as hard rubber, and these supports are in two pieces with an elastic cushion, d d, between them. This cushion may be of any suitable niiaterial as wire-gauze, felt, sponge, 850. When the instrument is used as a transmitter, one of these cushions is omitted and the upper block a is made in a single piece, as shown in Fig. 2.

Surrounding the electrodes and their supporting;blocks, and suitably connected to the latter at its extremities, is a coil, 0, of elastic material, preferably steel wire suitably insulated, and this is so arranged as to tend to separate the electrodes and hold them out of contact. Attached to or bearing upon the extreme supporting-blocks c, and in such a manner as to press them axially, are two elastic arms or tongs, ff, and these are properly hinged together and provided with means for adjusting themas aright and left hand screw, 9, the end of which may enter the block A, and thus form a support for the arms to keep them in proper position in the recess formed for their reception in the block. By means of this screw the pressure of the elastic arms upon the blocks carrying the electrodes may be regulated, and as they act in opposition to the spring-coil 6 they are preferably adjusted so that their force slightly preponderates over the force of the said spring, and the electrodes are thereby held in light elastic contact. The end of the outer support or block may have a slight projection or knob, h, which passes through a hole in the diaphragm, and serves to aid in retaining the spring-arm f in place, as well as to keep the block in proper relation to the diaphragm or sounding-board. It will be observed that by this construction the elec trodes are held by two counteracting forces or devices, the one tending to hinder or withdraw the electrodes from contact, and the other tending to complete or preserve their contact, and these forces may be adjusted so that the initial'contaet or relation of the elec trodes may be as delicate as desired.

An instrument constructed as above described may be used either as a transmitter or a receiver; but when used as a transmitter alone I dispense with the diaphragm or sounding-boardD and arrange the upper electrodesupporting block 0. immediately under or before the opening in the mouth -piece, as shown in Fig. 2, and a ring of rubber, z, or other material may be fitted over the projection on the support and into the recess in the block A to steady the support and keep it in proper position before the mouth-opening. The action of the receiver is based upon the repulsion of the electric current in passing 'between the two electrodes; and it will be reason that they had only a small contactsurface between the electrodes, and they were held together either rigidly or by forces acting only in one direction. In such instruments the disturbing effects of induction are not avoided.

I have found by actual experiment that by the use of fiat-faced electrodes, and supporting them by opposing forces when the telephones are simply connected upon a charged line, they can be successfully used in connection with lines running parallel to or in inductive relation therewith charged with other currents of whatever kind, and this I consider a very important result from the use of my instruments.

. WVhile I have found that the instruments may be successfully used with a light current, I prefer to use a comparatively heavy one, as the action is then more positive and the articulation is louder, and especially when used upon a circuit exposed to heavy inductive influences.

Having thus described my invention, without limiting myself to the precise details of construction set forth, which may be varied without departing from the spirit of my invention, what I claim is 1. In a telephone, the combination, substantially as herein set forth, of two electrodes, both axially acted upon by two counteracting devices, one tending to withdraw and the other to preserve contact between them.

2. In atelephone, the combination, substantially as herein set forth, of two electrodes, both axially acted upon by two counteracting devices, one tending to withdraw and the other to preserve contact between them, and adjusting devices for regulating their initial relations.

3. In atelephone, the combination, substantially as herein set forth, of two electrodes, both axially acted upon by two elastic counteracting 'devices, one tending to withdraw and the other to preserve contact between them.

4. The combination, substantially as herein set forth, of two flat-faced electrodes, supports for the same, a spring surrounding the electrodes and tending to withdraw them from contact, and an elastic device tending to preserve their contact, and adjusting devices for regulating their initial relations.

5. The combination, substantially as herein set forth, of a flat-faced carbon electrode, a flat-faced platinum electrode, non-conducting blocks for supporting them, elastic material interposed between the blocks, a spring connected to the blocks and surrounding the electrodes, a pair of arms or tongs connected to the blocks, and adjusting devices.

6. The combination, substantially as herein set forth, of a charged line and a set of telephones, each consisting, essentially, of flatfaced electrodes and counteracting devices acting axially upon both of the electrodes, one tending to make contact and the other to break contact in the manner set forth, whereby the disturbing effects of extraneous induction are not manifest in the receiving-instrument.

In testimony whereof Ihave signed my name to thisspecification in the presence of two subscribing witnesses.

WILLIAM G. LOOKWVOOD.

Witnesses:

L. G. YOUNG, J OHN G. HINKEL. 

